Transitional image for a portion of a display screen



FIG. 1 is a front view of the first image in the sequence for a transitional image for a portion of a display screen showing my new design; and,

FIG. 2 is a front view of the second image thereof.

The broken line showings of the portion of a display screen and the other features form no part of the claimed design. 

The ornamental design for an transitional image for a portion of a display screen, as shown and described. 